<body>
    <script src="include.js"></script>
    <script>
        test(() => {
            let mfrac = document.createElement("mfrac");
            let th = document.createElement("th");
            mfrac.appendChild(th);
            document.body.appendChild(mfrac);
            println("PASS (didn't crash)");
        });
    </script>
</body>
